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<html lang="en">
<head>
  <meta charset="UTF-8">
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  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>

  <style>
      #dev1{
            width:100%;
            height:1000px;
            background-image: url(./images/1.jpg);
            background-attachment: fixed; /*  */

      }
      #dev2{
            width:100%;
            height:1000px;
            background-image: url(./images/2.jpg);
            background-attachment: fixed;
      }
      #dev3{
            width:100%;
            height:1000px;
            background-image: url(./images/3.jpg);
            background-attachment: fixed;
      }
      
  </style>
</head>
    

<body>
  
  <div id="dev1">
      好多内容

  </div>
  <div id="dev2">
    好多内容

  </div>
  <div id="dev3">
    好多内容

  </div>
</body>
</html>